This invention relates to a grinding machine and a method for grinding a semiconductor device wafer. The grinding machine is designed to provide an automatic grinding operation for the manufacture of a semiconductor device wafer. More specifically, the grinding machine incorporates several automatic functions to aid in the grinding of a wafer, such as a rotary index table with dressing stations located thereon and an automatic loading and unloading device.
Wafer grinding machines are well-known in the art, however, prior art designs have several disadvantages which the present invention addresses. Typically, grinding machines are not capable of being used in a clean-room environment. This is due to the fact that these machines are too big and contain other integrated features such as wash stations. The present invention addresses this problem by creating a machine with a relatively small footprint that incorporates quick-connect connections for adding other equipment which can be located in another room.
Additionally, prior art machines do not incorporate dressing stations on the rotary index table. Some machines do not have dressing stations at all, but those that do locate the dressing stations adjacent the rotary index table. This results in the grinding spindles being mounted for both rotation in the horizontal plane and linearly in the vertical plane. This can cause alignment problems for the grinding wheels, diminishing the accuracy of the grinding process. This also results in lost time, as the grinding process is completely halted to allow the grinding wheels to rotate to the dressing station and then rotate back into position to continue grinding. The present invention addresses this problem by providing dressing stations located on the rotary index table. This allows the grinding spindles to be fixedly mounted to a linear motion system eliminating the need to rotate the grinding spindle.